scholarly journals Removing mains power artefacts from EEG – a novel template-based method

2020 ◽  
Author(s):  
Shenghuan Zhang ◽  
Brendan McCane ◽  
Phoebe S-H Neo ◽  
Neil McNaughton
Keyword(s):  
Notch Filter ◽  
Electrical Equipment ◽  
Noise Removal ◽  
Sine Wave ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Adaptive Notch Filter ◽  
Low Pass ◽  
Power Noise ◽  
Better Than

ABSTRACTEEG signals are often contaminated with artefacts, particularly with mains power from electrical equipment. Low-pass filtering and notch filtering can lose valuable data. Here we describe a novel mains power noise removal method based on the fact that mains power noise is a sine wave component with an essentially fixed frequency and the same phase across all channels. This removes the blink component, leaving uncontaminated EEG largely unchanged. Blink removal had a success rate of >99.9% recovered variance of the original EEG when removing synthesised mains power components. We compared this method with two other popular mains power noise removal methods. Our method was better than Cleanline which is an ICA based method and multiple PLI which is an adaptive notch filter based method. With the higher recovery, our method shows clear advantages over Cleanline and multiple PLI for removing mains power noise. From the aspect of data loss, it is obviously better than low-pass filter and normal notch filter.

scholarly journals Detection and Reduction of Middle-Frequency Resonance for Industrial Servo with Self-Tuning Lowpass Filter

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Wen-Yu Wang ◽  
An-Wen Shen
Keyword(s):  
Notch Filter ◽  
Corner Frequency ◽  
Frequency Range ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Frequency Resonance ◽  
Adaptive Notch Filter ◽  
Frequency Detection ◽  
Self Tuning ◽  
The Difference

A novel method for middle frequency resonance detection and reduction is proposed for speed control in industrial servo systems. Defects of traditional resonance reduction method based on adaptive notch filter in middle frequency range are analyzed. And the main reason is summarized as the difference between the resonance frequency and the oscillation frequency. A self-tuning low-pass filter is introduced in the speed feedback path, whose corner frequency is determined by FFT results and several self-tuning rules. With the proposed method the effective range of the adaptive filter is extended across the middle frequency range. Simulation and Experiment results show that the frequency detection is accurate and resonances during the speed steady states and dynamics are successfully reduced.

Design of a Sine Sweeping Constant Current Source Based FPGA and DDS

2014 ◽  
Vol 936 ◽  
pp. 2230-2234
Author(s):  
Ya Ping Yu ◽  
Hui Zhao ◽  
Yuan Liu ◽  
Ren Jie Yang ◽  
Gui Mei Dong ◽  
...  
Keyword(s):  
Frequency Control ◽  
Current Source ◽  
Sine Wave ◽  
Constant Current ◽  
Constant Current Source ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Fpga Chip ◽  
Sine Wave Generator

This paper designed a range of 0.1 ~ 250 kHz sine wave sweeping constant current source, which sine wave generator based on FPGA chip and DDS technology, the desired sine wave frequency was obtained by controlling the frequency control words. Low-pass filter circuit was realized by using the LTC1560-1, conversion circuit from the voltage to the current was consisted of a Howland current pump. The constant current source shows a good spectral impedance purity and amplitude.

scholarly journals The Design of Terahertz Frequency Quadruplers Based on Discrete Schottky Diodes

Micromachines ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 69
Author(s):  
Yuhang Li ◽  
Dehai Zhang ◽  
Jin Meng ◽  
Haotian Zhu ◽  
Siyu Liu
Keyword(s):  
Output Power ◽  
Schottky Diodes ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Peak Output Power ◽  
W Band ◽  
Low Pass ◽  
Matching Structure ◽  
Better Than ◽  
Gradient Line

On the basis of the W-band power source, a single-stage frequency quadrupler method was used to implement two 335 GHz frequency quadruplers. The two frequency quadruplers adopted a traditional binomial matching structure and an improved gradient line matching structure, respectively. An idle loop was added to the overall circuit in the design of the DC filter and low-pass filter. The improved gradient line matching structure reduced the circuit length while increasing the bandwidth, effectively reducing the power loss on the transmission line. A micro-strip circuit was fabricated with a 50 μm thick quartz circuit and was mounted onto a split waveguide block. The results showed that the output power of the quadrupler with the improved matching structure was better than that of the quadrupler with the conventional matching structure. The peak output power of the improved frequency quadrupler was 4.75 mW at 333 GHz when driven with 200 mW. In contrast, this improved structure broadened the bandwidth by 8 GHz and reduced the length of the substrate by 0.607 mm, effectively reducing the length of the traditionally designed circuit by 11.5%.

scholarly journals Portable Electrocardiograph Dengan Sadapan Pada Telapak Tangan Dan Kaki

2020 ◽  
Vol 13 (2) ◽  
pp. 107-114
Author(s):  
Muhammad Syifaul Linnas ◽  
Sumber Sumber ◽  
Prastawa Assalim Tetraputra
Keyword(s):  
Personal Computer ◽  
Notch Filter ◽  
Pass Filter ◽  
Low Pass Filter ◽  
High Pass Filter ◽  
Low Pass ◽  
High Pass

    Electrocardiograph (ECG) secara rutin dilakukan oleh operator terampil yang terbiasa dengan penempatan masing-masing elektroda pada pasien. Posisi elektroda yang salah dapat menyebabkan kesalahan kritis dalam diagnosis dan perawatan penyakit jantung. Tujuan dari penelitian ini adalah mendesain sebuah Portable Electrocardiograph dengan Sadapan Pada Telapak Tangan dan Kaki. Kontribusi dari penelitian ini adalah  memudahkan orang awam dalam bidang kesehatan dalam hal penggunaan Electrocardiograph. Penelitian ini juga bertujuan  mendesain Electrocardiograph yang cukup terjangkau bagi puskesmas/pusat-pusat pelayanan medis di daerah. Agar desain ini dapat memudahkan dalam metode penggunaan alat, maka dibuatlah alat Electrocardiograph (ECG) dengan elektroda pad yang akan diletakkan pada telapak tangan dan telapak kaki yang telah di berikan tanda pada elektroda tersebut. Electrocardiograph (ECG) menggunakan desain High Pass Filter (Pasif 20dB ditambah Non Inverting Amplifier, Low Pass Filter (LPF) 40dB, dan notch filter yang akan ditampilkan pada layar monitor Personal Computer (PC). Dari hasil sadapan beberapa responden, terlihat hasil tampilan yang menyerupai/mendekati sinyal Electrocardiograph (ECG) sebenarnya. Kekurangan dari modul ini jika tidak adanya grounding yang baik dari power suply maka akan terjadi noise pada hasil sinyal yang akan ditampilkan. Hasil penelitian ini dapat di implementasikan pada Electrocardiograph (ECG) konvensional untuk meningkatkan kemudahan dalam hal penggunaan alat.    

The Design and Simulation of DDS Based on Multisim and C51

2013 ◽  
Vol 416-417 ◽  
pp. 1368-1372
Author(s):  
Jie Ma
Keyword(s):  
Frequency Synthesizer ◽  
Circuit Simulation ◽  
Frequency Control ◽  
Sine Wave ◽  
Control Word ◽  
Clock Frequency ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Control Center ◽  
Low Pass

In order to facilitate intuitive and understanding of the frequency synthesizer technology, research on direct digital frequency synthesizer by the phase accumulator , waveform storage ROM, the D/ Aconverter and low-pass filter modules .Multisim provides powerful virtual electronic platform, realize DDS synthetic sine wave design and circuit simulation by C51 MCU control center, while providing key code. By adjustingthe reference clock frequency fc, or to adjust the frequency control word K, can be clearly seen of the frequency of the synthesized sine wave will be changed.

Harmonic Detection Based on Improved Adaptive Method and its Performance

2011 ◽  
Vol 291-294 ◽  
pp. 2620-2623
Author(s):  
Jun Min Zhang
Keyword(s):  
Dynamic Performance ◽  
Harmonic Distortion ◽  
Notch Filter ◽  
Adaptive Method ◽  
Reference Frequency ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Detecting Method ◽  
Adaptive Detecting

In this paper, according to the base-adaptive detecting method of harmonic current for APF, there had contradiction between detecting accuracy and dynamic response. It had been proved that this system is a symmetrical notch-filter. Based on analysis above, this paper is proposed improved-adaptive detecting method. A low-pass filter has been in base-adaptive system. We first discussed the stability of improved system. Then theoretical analysis and simulation test shows the bandwidth had been reduced nearby reference frequency. Simulation had showed that the dynamic performance was in a period and the harmonic distortion rate was no more than 1.7%.

scholarly journals Evolutionarily stable mutation rate in a periodically changing environment.

Genetics ◽  
1989 ◽  
Vol 121 (1) ◽  
pp. 163-174 ◽  
Author(s):  
K Ishii ◽  
H Matsuda ◽  
Y Iwasa ◽  
A Sasaki
Keyword(s):  
Mutation Rate ◽  
Selection Pressure ◽  
Sine Wave ◽  
Fluctuating Selection ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Haploid Population ◽  
The Cost ◽  
Evolutionarily Stable

Abstract Evolution of mutation rate controlled by a neutral modifier is studied for a locus with two alleles under temporally fluctuating selection pressure. A general formula is derived to calculate the evolutionarily stable mutation rate mu(ess) in an infinitely large haploid population, and following results are obtained. (I) For any fluctuation, periodic or random: (1) if the recombination rate r per generation between the modifier and the main locus is 0, mu(ess) is the same as the optimal mutation rate mu(op) which maximizes the long-term geometric average of population fitness; and (2) for any r, if the strength s of selection per generation is very large, mu(ess) is equal to the reciprocal of the average number T of generations (duration time) during which one allele is persistently favored than the other. (II) For a periodic fluctuation in the limit of small s and r, mu(ess)T is a function of sT and rT with properties: (1) for a given sT, mu(ess)T decreases with increasing rT; (2) for sT </= 1, mu(ess)T is almost independent of sT, and depends on rT as mu(ess)T & 1.6 for rT < 1 and mu(ess)T & 6/rT for rT > 1; and (3) for sT >/= 1, and for a given rT, mu(ess)T decreases with increasing sT to a certain minimum less than 1, and then increases to 1 asymptotically in the limit of large sT. (III) For a fluctuation consisting of multiple Fourier components (i.e., sine wave components), the component with the longest period is the most effective in determining mu(ess) (low pass filter effect). (IV) When the cost c of preventing mutation is positive, the modifier is nonneutral, and mu(ess) becomes larger than in the case of neutral modifier under the same selection pressure acting at the main locus. The value of c which makes mu(ess) equal to mu(op) of the neutral modifier case is calculated. It is argued that this value gives a critical cost such that, so long as the actual cost exceeds this value, the evolution rate at the main locus must be smaller than its mutation rate mu(ess).

scholarly journals Design Engineering Instrumental Carotid Pulse System in Analitical Heart’s Dinamyc With Continuous Wavelet Transform Method

2016 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Eko Agus Suprayitno ◽  
Indah Sulistyowati ◽  
Izza Anshory ◽  
Jamaaluddin Jamaaluddin
Keyword(s):  
Wavelet Transform ◽  
Notch Filter ◽  
Design Engineering ◽  
Continuous Wavelet ◽  
Pulse System ◽  
Transform Method ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Quality Factor Q

Klasifikasi sinyal Carotid Pulse sangat penting untuk mengetahui proses terjadinya tekanan darah dalam mengalirkan darah melewati katup-katup jantung menuju ruang-ruang jantung dan paru-paru serta mendukung analisa suara jantung yang ada untuk mendeteksi murmur, mengklasifikasikan suara jantung normal dan tidak normal, serta untuk menjelaskan dinamika jantung, oleh sebab itu pada penelitian ini dilakukan beberapa pekerjaan pendahuluan pada pembuatan instrumentasi pendeteksian sinyal tekanan darah (Carotid Pulse).Pada penelitian ini dihasilkan informas Low Pass Filter Analog Orde 4 dengan frekuensi cutoff 100 Hz penguatan -3 dB terjadi di area frekuensi 120 Hz. Hasil uji Notch Filter dihasilkan tegangan output terkecil di frekuensi 50 Hz dengan besar Vout (0.14 ± 0.00) volt dengan Quality factor (Q) sebesar 6.28. Analisa sinyal Carotid Pulse dengan DFT memberikan informasi bahwa pada tekanan darah, area frekuensinya di antara 1 Hz sampai 20 Hz. Sinyal Carotid Pulse untuk siklus pertama Frekuensi tertingginya (6.81 ± 0.41) Hz dan merupakan gelombang P yang menggambarkan kenaikan Carotid Pulse secara tiba-tiba dari pemompaan darah pada ventrikel kiri menuju aorta hinggga mencapai puncak. Analisa dengan menggunakan CWT menghasilkan data keterangan waktu yang menunjukkan waktu terjadinya frekuensi tertinggi sinyal Carotid Pulse. Penelitian ini selanjutnya akan dikembangkan pada Multimodal Cardiac Analysis untuk mendapatkan informasi anatomi dan fisiologi jantung yang lebih kompleks.

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